Key Differences Between Groups and Periods in the Periodic Table

1. What They Are:

   • Groups: These are the vertical columns in the periodic table, numbered from 1 to 18. Elements in the same group share similar chemical traits.
   • Periods: These are the horizontal rows, numbered from 1 to 7. The periods show how many electron shells an element has.

2. What They Have in Common:

   • Elements that are in the same group have the same number of valence electrons, which are the electrons involved in chemical reactions.
   • Some properties, like how reactive an element is or its electronegativity (which tells us how well it attracts electrons), can go up or down as you move along groups or periods.

3. Some Facts:

   • Group 1, also known as Alkali Metals, has 6 elements.
   • Period 3, which goes from Sodium (Na) to Argon (Ar), has 8 elements.

4. Trends to Notice:

   • As you go down a group, you’ll see certain properties change in a particular way.
   • As you move from left to right across a period, you’ll also see changes in those properties.